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Oaths of Damnation
An Exorcists Novel
The Exorcists are a Space Marine Chapter unlike any other. To combat the forces of Chaos, they willingly accept daemonic possession, knowing that once it is purged their shattered souls will no longer be susceptible to corruption. Those who fail the banishment trials become Broken Ones – living prisons for the terrors expelled from their brethren. Should such desperate measures become known to the wider Imperium, the Chapter would stand accused of the vilest of heresies.
READ IT BECAUSE
Discover what happens when a Broken One is freed, and a daemonic conspiracy threatens to unveil the dark rituals of the Exorcists.
THE STORY
The Exorcists dispatch their Vanguard elite, the Hexbreakers, in a desperate quest to hunt down a Broken One, but the connection between their quarry and the strike force commander, Daggan Zaidu, is more than it first appears.
The Exorcists are a Space Marine Chapter unlike any other. To combat the forces of Chaos, they willingly accept daemonic possession, knowing that once it is purged their shattered souls will no longer be susceptible to corruption. Those who fail the banishment trials become Broken Ones – living prisons for the terrors expelled from their brethren. Should such desperate measures become known to the wider Imperium, the Chapter would stand accused of the vilest of heresies.
READ IT BECAUSE
Discover what happens when a Broken One is freed, and a daemonic conspiracy threatens to unveil the dark rituals of the Exorcists.
THE STORY
The Exorcists dispatch their Vanguard elite, the Hexbreakers, in a desperate quest to hunt down a Broken One, but the connection between their quarry and the strike force commander, Daggan Zaidu, is more than it first appears.
384 pages, Paperback
First published August 24, 2024
100 people are currently reading
224 people want to read
About the author
Robbie MacNiven
123 books116 followersRobbie MacNiven is a Scottish author and historian. His published fiction includes over a dozen novels, many fantasy or sci-fi works for IPs such as Warhammer 40,000 and Marvel's X-Men. He has also written two novellas, numerous short stories and audio dramas, has worked on narrative and character dialogue for multiple digital games (SMITE: Blitz and Age of Sigmar: Storm Ground), has written the colour text for multiple RPG rulebooks and has penned the scripts for two graphic novels and three comics, for Osprey Publishing and Commando Comics respectively. In 2022 his X-Men novel "First Team" won a Scribe Award.
On the non-fiction front, Robbie specialises in Early Modern military history, particularly focussing on the 18th century. He has a PhD in American Revolutionary War massacres from the University of Edinburgh - where he won the Compton Prize for American History - and an MLitt in War Studies from the University of Glasgow. Along with numerous articles for military history magazines he has written six books on different aspects of the American Revolutionary War, five for Osprey Publishing and one for Helion Books. He has also written the scripts for ten episodes of the hit YouTube educational channel Extra Credits.
Outside of work and writing, his passions include re-enacting, gaming, and football.
On the non-fiction front, Robbie specialises in Early Modern military history, particularly focussing on the 18th century. He has a PhD in American Revolutionary War massacres from the University of Edinburgh - where he won the Compton Prize for American History - and an MLitt in War Studies from the University of Glasgow. Along with numerous articles for military history magazines he has written six books on different aspects of the American Revolutionary War, five for Osprey Publishing and one for Helion Books. He has also written the scripts for ten episodes of the hit YouTube educational channel Extra Credits.
Outside of work and writing, his passions include re-enacting, gaming, and football.
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Displaying 1 - 30 of 31 reviews
October 3, 2025
A fantastic book about the Exorcists, a space marine legion I had previously never knew about. The story was fantastic and how they described how the exorcists gained their powers, by letting themselves get possessed by a warp daemon and then banishing it, and what happens to the initiates that fail was phenomenal. I loved the authors take on occult and witchcraft cultures mixed into one for the Exorcists. Finally, I love the depiction of the warp, with them showing and describing how twisted and evil it is and how it shatters normal minds. After this book, these guys are now one of my favorite space marine legions, just behind the Carcharodons.
July 21, 2025
I am NOT okay somebody come hug me.
No spoilers: a great read. It starts creepy and ominous and introduces one of the more weird and hard to love chapters, the Exorcists. Don't worry, ya girl managed to fall in love with them anyway. I could read Anu and Cy'Leth all. freakin. DAY.
The basic Exorcist gist (not spoilering anything that's not on a wiki) is that they allow themselves to be possessed by warp critters as neophytes and those that have the ability and will to fight it off become Exorcists and those who don't become Broken Ones. The ones who do survive have very little 'soul' left which is why they are hard to relate to as one does traditional characters.
This is where MacNiven has a hard road but he does it well: because he's not even writing just about the USUAL transhuman slight weirdness of Astartes. These guys are VERY not human. And he does an amazing job capturing their non human ness.
The combat scenes are super well written--a lot of Warhammer writers suddenly go 10,000 feet up and get a weird historical voice like they're narrating a documentary about the battle, but MacNiven really has a gift of showing the combat POV by POV.
And Lore? Do you like LORE? Because there's so much Exorcist lore (the various orisons etc) that you will go NUTS with all this Lore.
And the end made me cry my face off. Absolutely bleak and grimdark. I love it.
He and Peter Fehervari are my absolute all stars for Warhammer writing.
No spoilers: a great read. It starts creepy and ominous and introduces one of the more weird and hard to love chapters, the Exorcists. Don't worry, ya girl managed to fall in love with them anyway. I could read Anu and Cy'Leth all. freakin. DAY.
The basic Exorcist gist (not spoilering anything that's not on a wiki) is that they allow themselves to be possessed by warp critters as neophytes and those that have the ability and will to fight it off become Exorcists and those who don't become Broken Ones. The ones who do survive have very little 'soul' left which is why they are hard to relate to as one does traditional characters.
This is where MacNiven has a hard road but he does it well: because he's not even writing just about the USUAL transhuman slight weirdness of Astartes. These guys are VERY not human. And he does an amazing job capturing their non human ness.
The combat scenes are super well written--a lot of Warhammer writers suddenly go 10,000 feet up and get a weird historical voice like they're narrating a documentary about the battle, but MacNiven really has a gift of showing the combat POV by POV.
And Lore? Do you like LORE? Because there's so much Exorcist lore (the various orisons etc) that you will go NUTS with all this Lore.
And the end made me cry my face off. Absolutely bleak and grimdark. I love it.
He and Peter Fehervari are my absolute all stars for Warhammer writing.
January 17, 2025
This has to be one of the best 40K books I’ve read in a while (excluding some Horus heresy books) this book did not slow down once! Literally 1 paragraph in and a psycher gouges out her eyes and eats them from the insanity within the warp. The Exorcists chapter was also made just for me I feel. The guys get possessed by demons then cast them out so they cannot be possessed again and then go hunt demons it’s just awesome! The fighting was excellent and the demons were particularly horrific honestly I have no complaints what so ever!
October 4, 2024
So far so good. Robbie.M seems to be standing out as the de facto ‘writer of obscure chapters’ author, and that’s fine with me. Really enjoyed this one.
September 18, 2024
So here's a catch-22 for you - the Exorcists might be one of the coolest Space Marine concepts ever, but they're not much fun to read about. I want to stress that Oaths of Damnation is by no means a bad book, but it was unfortunately a DNF at the halfway mark for me.
A chapter all about recruits wilfully possessing themselves with daemons then purging them in order to gain resistance to later possessions is such a great conceit. Graham McNeill wrote a fantastic short story about their initiation rites in the Successors anthology. Some of those rites are also explored in this book, including a very gnarly campfire ritual that would've benefited from some marshmallow-toasting to break the tension. Throughout the book there's a thin thread about the trauma embedded in each marine as a result of their exorcism, which manifests through literal resurgence of daemonic traits like evil teeth and bone spurs that require other marines to saw them off. The Exorcists are hardened, burned out, borderline heretical servants of the God-Emperor, their souls broken by their initiation. The idea behind them is as cool as the hell from which their daemons are drawn.
Unfortunately, because of all that hardened burned out-ness, they're not great POV characters. All the Exorcist protagonists aren't that interesting and have little variety or depth; many of them read as if they're the same character. The central quest to locate a daemon-possessed marine gone rogue gets bogged down by many similar chapters of marines killing heretics and ruminating on their literal daemons still being connected to them. The Chaos character POVs, which can usually be counted on to provide some welcome villainous contrast via their raving and worshipping evil dark gods, also aren't as intriguing as in other marine-heavy books. Most of it largely boils down to a simple, Imperium vs Chaos battle on a crapsack world.
Oaths of Damnation is a decent marine-focused combat story but lacks satisfying exploration of the facets that make the Exorcists such a cool chapter.
A chapter all about recruits wilfully possessing themselves with daemons then purging them in order to gain resistance to later possessions is such a great conceit. Graham McNeill wrote a fantastic short story about their initiation rites in the Successors anthology. Some of those rites are also explored in this book, including a very gnarly campfire ritual that would've benefited from some marshmallow-toasting to break the tension. Throughout the book there's a thin thread about the trauma embedded in each marine as a result of their exorcism, which manifests through literal resurgence of daemonic traits like evil teeth and bone spurs that require other marines to saw them off. The Exorcists are hardened, burned out, borderline heretical servants of the God-Emperor, their souls broken by their initiation. The idea behind them is as cool as the hell from which their daemons are drawn.
Unfortunately, because of all that hardened burned out-ness, they're not great POV characters. All the Exorcist protagonists aren't that interesting and have little variety or depth; many of them read as if they're the same character. The central quest to locate a daemon-possessed marine gone rogue gets bogged down by many similar chapters of marines killing heretics and ruminating on their literal daemons still being connected to them. The Chaos character POVs, which can usually be counted on to provide some welcome villainous contrast via their raving and worshipping evil dark gods, also aren't as intriguing as in other marine-heavy books. Most of it largely boils down to a simple, Imperium vs Chaos battle on a crapsack world.
Oaths of Damnation is a decent marine-focused combat story but lacks satisfying exploration of the facets that make the Exorcists such a cool chapter.
October 2, 2024
I dont like leaving bad reviews for someones work but I really struggled to get through this book. I am not really a fan of most loyalist chapters as the characters usually are much less interesting than chaos to me but the concept of the exorcists intrigued me. However, there wasnt a single interesting character in this book for me and it just turned into bolter porn which had my mind wondering elsewhere throughout it. I also found the the dialog similar to bad movie dialog and not in a campy fun way.
October 5, 2025
This book was just OK for me.
Not really a fan of the Exorcists so I didn’t find it all that engaging of a read. I found the POV’s of the Wordbearers in the story to be much more interesting and has kind of made me want to try out some of their books.
I do like Robbie Macniven’s books, just didn’t find this one great.
Not really a fan of the Exorcists so I didn’t find it all that engaging of a read. I found the POV’s of the Wordbearers in the story to be much more interesting and has kind of made me want to try out some of their books.
I do like Robbie Macniven’s books, just didn’t find this one great.
This entire review has been hidden because of spoilers.
February 27, 2025
"What if the most superstitious of the Black Templars also became daemonhosts?" If that sounds intriguing to you, here's your book.
August 7, 2025
Surprisingly enjoyable on an accidental re-read. There's a lot of subtle character work going on, despite this being basic bolter porn. But the Exorcists are mission-focused and that allows us to ignore the overall conflict, something a lot of BL authors have trouble conveying these days.
October 25, 2024
Dorn is dull.
MacNiven's Imperial Fists successors Chapter beats chaos daemons with boredom.
No Carcharodons chainaxe glory here.
MacNiven's Imperial Fists successors Chapter beats chaos daemons with boredom.
No Carcharodons chainaxe glory here.
January 8, 2025
Heavy on the bolter porn, light on story.
September 28, 2024
Rating of 4.5.
Prepare to follow the most damned heroes in the Warhammer 40,000 canon in the impressive and intense new novel from Robbie MacNiven, Oaths of Damnation.
In the far, war-torn future, the Imperium of Man is under constant attack from the forces of the Chaos gods and their deadly daemon servants. Few within the Imperium, even amongst the legendary Space Marines of the Adeptus Astartes, can fight against the daemons of Chaos on an equal footing, but there is one Space Marines Chapter, the Exorcists, that takes the battle to them in the most unorthodox and heretical of ways.
The Exorcists are an elite and secretive Chapter of Space Marines who make the ultimate sacrifice to fight the forces of Chaos. Willingly accepting daemonic possession as part of their initiation, prospective Exorcists need to banish the daemon within themselves to join the Chapter. Those who succeed become fierce warriors who are now resistant to the corruption of Chaos at the cost of their own fractured souls. However, those that fail suffer a fate worse than death as they become Broken Ones, living prisons for the daemons summoned and expelled by the rest of the Chapter. Few in the Imperium know the sacrifices that this Chapter makes to fight the enemy; if it were to become common knowledge, all the Exorcists would be put to the flame as heretics.
As such, when a dark conspiracy sees a Broken One containing a powerful daemon, the Red Marshal, escape from the Exorcists custody, the Chapter sends a unit of its elite Hexbreakers to hunt it down before their secrets are exposed. Led by the dogged Almoner-Lieutenant Daggan Zaidu and powerful psyker Codicier Torrin Vey, the Exorcists strike force journeys to Fidem IV, a planet littered with ancient battlefields, to hunt down the Broken One and destroy the daemons within.
But as the Exorcists battle across the planet looking for their prey, it soon becomes clear that members of the Word Bearers traitor Space Marines Legion are on Fidern IV, seeking the Broken One for their own sinister purposes. Worse, a dangerous connection exists between Zaidu and the Red Marshal, one that could endanger the entire mission. Can the Hexbreakers succeed and hunt down the Broken One before it is too late, or will their Chapter’s darkest secret be unleashed upon the entire Imperium in a wave of blood?
Oaths of Damnation was a particularly intriguing and intense Warhammer 40,000 novel that really showcased MacNiven’s skill as an author. Featuring a detailed look at a particularly cool faction in the Warhammer 40,000 canon, Oaths of Damnation was an excellent and exciting read that constantly grabbed my attention and refused to let go.
To see the full review, click on the link below:
https://unseenlibrary.com/2024/09/28/...
For other exciting reviews and content, check out my blog at:
https://unseenlibrary.com/
Prepare to follow the most damned heroes in the Warhammer 40,000 canon in the impressive and intense new novel from Robbie MacNiven, Oaths of Damnation.
In the far, war-torn future, the Imperium of Man is under constant attack from the forces of the Chaos gods and their deadly daemon servants. Few within the Imperium, even amongst the legendary Space Marines of the Adeptus Astartes, can fight against the daemons of Chaos on an equal footing, but there is one Space Marines Chapter, the Exorcists, that takes the battle to them in the most unorthodox and heretical of ways.
The Exorcists are an elite and secretive Chapter of Space Marines who make the ultimate sacrifice to fight the forces of Chaos. Willingly accepting daemonic possession as part of their initiation, prospective Exorcists need to banish the daemon within themselves to join the Chapter. Those who succeed become fierce warriors who are now resistant to the corruption of Chaos at the cost of their own fractured souls. However, those that fail suffer a fate worse than death as they become Broken Ones, living prisons for the daemons summoned and expelled by the rest of the Chapter. Few in the Imperium know the sacrifices that this Chapter makes to fight the enemy; if it were to become common knowledge, all the Exorcists would be put to the flame as heretics.
As such, when a dark conspiracy sees a Broken One containing a powerful daemon, the Red Marshal, escape from the Exorcists custody, the Chapter sends a unit of its elite Hexbreakers to hunt it down before their secrets are exposed. Led by the dogged Almoner-Lieutenant Daggan Zaidu and powerful psyker Codicier Torrin Vey, the Exorcists strike force journeys to Fidem IV, a planet littered with ancient battlefields, to hunt down the Broken One and destroy the daemons within.
But as the Exorcists battle across the planet looking for their prey, it soon becomes clear that members of the Word Bearers traitor Space Marines Legion are on Fidern IV, seeking the Broken One for their own sinister purposes. Worse, a dangerous connection exists between Zaidu and the Red Marshal, one that could endanger the entire mission. Can the Hexbreakers succeed and hunt down the Broken One before it is too late, or will their Chapter’s darkest secret be unleashed upon the entire Imperium in a wave of blood?
Oaths of Damnation was a particularly intriguing and intense Warhammer 40,000 novel that really showcased MacNiven’s skill as an author. Featuring a detailed look at a particularly cool faction in the Warhammer 40,000 canon, Oaths of Damnation was an excellent and exciting read that constantly grabbed my attention and refused to let go.
To see the full review, click on the link below:
https://unseenlibrary.com/2024/09/28/...
For other exciting reviews and content, check out my blog at:
https://unseenlibrary.com/
November 22, 2025
I first want to say that I love the concept of the Exorcists. As a whole the Chapter itself is interesting. Unfortunately, the issue with the book comes down to the plot and the characters. Plot really didn’t go anywhere until the last 60 pages, and I still don’t understand why the Red Marshals existence would be a risk to the Chapter being called traitor? ? Didn’t make sense. Also too many character perspectives. Didn’t feel like any character was explored and it was hard to remember who some of these Exorcists were
August 28, 2024
Sons of Dorn?
If he ever returns this chapter will be joining Horus in the immaterium!,
Did no one ever wonder what a chapter called The Exorcists was actually up to ?
I had no real knowledge of them and that’s why I find this book fascinating
Really enjoyed it
Not so keen on the choice of narrator
He did a very good job on Bloodlines but sadly this was not his best
If he ever returns this chapter will be joining Horus in the immaterium!,
Did no one ever wonder what a chapter called The Exorcists was actually up to ?
I had no real knowledge of them and that’s why I find this book fascinating
Really enjoyed it
Not so keen on the choice of narrator
He did a very good job on Bloodlines but sadly this was not his best
January 7, 2026
Another foolish business decision by warhammer 40k. Females are a minority of your readers. This book is mostly female characters. I am a male. I do read sororitas books, or books like the one with female characters I have seen before. But this is just pandering to females. Wake up wh40k, I am close to stopping reading the ENTIRE series. This is disgusting.
September 28, 2024
Think this is my favourite Black Library book of the past couple of years. It’s great to see Robbie writing space marines again, and as much as I love his Charcardons books, this is better. Good story and a great deep dive into an one of the more mysterious fan favourite chapters.
June 30, 2025
Good look at a unique story
Very interesting to read the obstacles faced by lesser-known chapters. This book does a great job detailing the specifics of the chapter's organization while providing an intimate look into the lives of daemons. Very fun read.
Very interesting to read the obstacles faced by lesser-known chapters. This book does a great job detailing the specifics of the chapter's organization while providing an intimate look into the lives of daemons. Very fun read.
October 14, 2025
A great look into one of my favorite chapters. Story never really ventures away from the Space Marine protagonists and I think it suffers for it. Lots of fun moments and fighting. If you like 40k and grim Space Marines this will right up your alley.
October 22, 2025
A fascinating dive into the Exorcists Chapter, really cool to see all the dodgy and somewhat heretical things they get up to. Along with a healthy dose of the action we can expect from 40k. Definitely on the more action heavy side but it did make the pauses between more meaningful.
December 26, 2025
So far, this book has been hard to read through. There’s a lot going on, which at first, I thought was pretty cool. However, it has become difficult to keep up with all the names of characters who are briefly in the book. The writing could have been better in my opinion.
November 14, 2024
This was not good. It felt more like an advertisement for new minis than a story. PASS.
November 20, 2024
Super fun read.
I wanted space marines fighting daemons, and that's exactly what i got. Full of action with some horror. Loved learning more about the exorcists chapter. It's definitely a must-read.
I wanted space marines fighting daemons, and that's exactly what i got. Full of action with some horror. Loved learning more about the exorcists chapter. It's definitely a must-read.
February 18, 2025
Such an interesting look into the infamous Exorcist space marine chapter. Lots of cool lore bits, characters, and action of course.
June 8, 2025
Edgy, repetitive. and overall boring.
November 6, 2025
Robbie did a great job of diving into a little known chapter and fleshing out their culture. As well as writing a really good heretic astartes character. Thoroughly enjoyable.
November 20, 2025
Kept me wanting to read more
December 11, 2025
enjoyable. Finally, a "what-if " scenario made lore of a chapter that is of anti-greyknight
September 14, 2025
an interesting dive into a chapter that has few other stories to my knowledge.
The overall story is fairly straightforward.
not too many bills and whistles going on.
but I would say that is to this book's strength as it is the characters that I found most interesting.
despite being supposedly soulless they had more distinction than the vast majority of bland space Marines from other books.
I particularly like the sniper and the librarian.
both being types of space Marines that she don't get the POV of very much.
usually they're just side characters but in this one they take much more of up front roll.
we get to truly see what a librarian can do when they go all out.
and just tell valuable a sniper truly is on any battlefield.
far too often space Marines are betrayed as generalists, with bolster and chainsword.
I like that the specialists are getting more of a spotlight now.
I look forward to seeing what other stories might come about from this chapter.
as they're basically the darker reflection of the Gray knights, which is just an amazing concept as is.
The overall story is fairly straightforward.
not too many bills and whistles going on.
but I would say that is to this book's strength as it is the characters that I found most interesting.
despite being supposedly soulless they had more distinction than the vast majority of bland space Marines from other books.
I particularly like the sniper and the librarian.
both being types of space Marines that she don't get the POV of very much.
usually they're just side characters but in this one they take much more of up front roll.
we get to truly see what a librarian can do when they go all out.
and just tell valuable a sniper truly is on any battlefield.
far too often space Marines are betrayed as generalists, with bolster and chainsword.
I like that the specialists are getting more of a spotlight now.
I look forward to seeing what other stories might come about from this chapter.
as they're basically the darker reflection of the Gray knights, which is just an amazing concept as is.
Displaying 1 - 30 of 31 reviews